The use of polymeric materials in hair care products is of increasing importance. In the hair care area, polymers can be used for hair hold and setting products, for hair conditioning products, and in shampoos. For example, rinse-off hair care conditioning/styling products typically comprise a hydrophobic polymer which remains after rinsing the hair. The polymer is solubilized in a suitable solvent which evaporates to leave the polymer treated hair. The solvent must be one in which the polymer is substantially soluble (i.e., the solvent is generally hydrophobic).
A hair styling polymer should provide certain styling benefits. For example, the styling polymer should not leave the hair feeling and looking coated. Also, the styling polymer should have sufficient adhesion without being unduly brittle such that the hair can be restyled, e.g. with heated implements, and then maintain the new style. Still in addition, the styling polymer should be deliverable from a shampoo matrix, i.e., it should deposit on the hair during the washing process and remain behind on the hair fibers. Therefore, in the hair styling area, it is desirable to provide polymers which provide improved styling benefits and which can be delivered from a wide variety of matrices, including rinses, leave-on compositions, and shampoos. It is also desirable to provide hair styling compositions which have improved hair feel performance (after application and drying of such compositions) at a particular level of hair conditioning or conversely, improved hair conditioning for a particular level of hair feel performance.
It is well known that polymers can be modified by the incorporation or grafting of silicone. Such polymers have been used heretofore in hair care compositions. See, e.g., U.S. Pat. No. 5,106,609, to R. E. Bolich Jr., et al. issued Apr. 21, 1992; U.S. Pat. No. 4,693,935, to Mazurek, issued Sep. 15, 1987; PCT U.S. application Ser. No. 94/08031, published Feb. 16, 1995, and PCT U.S. application Ser. No. 94/09503, published Mar. 2, 1995. Silicone grafted polymers tend to have a low surface energy and provide unique aesthetic and formulation advantages not usually obtained from non-silicone grafted polymers. Nonetheless, for improved hair adhesion/hold, conditioning, industrial hygiene, formulation opportunities, and/or economics, it is desirable to have alternative, non-silicone polymer based compositions which meet or approach the hair feel properties provided by silicone polymer based materials.
Non-silicone, hydrophobic graft copolymers are well known in the art, but have not been used for personal care applications, such as hair care products. See, e.g., Chemistry and Industry of Macromonomers, Yuya Yamashita (ED.), Huthig & Wepf, New York, 1993; and Macromolecular Design Concept and Practice, Munmaya K. Mishra (Ed.), Polymer Frontiers International, Inc. New York, 1994. Despite the advantages that non-polar graft copolymers can provide, these materials are generally difficult to formulate in solvents used in the personal care industry. It has been found, however, in the present invention that the use of certain hydrophobic, volatile solvents provides a highly desirable basis for these compositions. The resulting compositions have good styling and conditioning performance and have a highly desirable feel upon the hair, i.e. they do not leave the hair feeling unacceptably stiff or sticky.
The graft copolymers of the present invention are non-silicone, hydrophobic materials, being relatively insoluble in water and/or alcohol and having certain thermomechanical properties. These characteristics make these copolymers highly useful for formulation in hair care products.
It is an object of the present invention to provide novel hair care compositions containing non-silicone, nonpolar graft copolymers.
It is another object of the present invention to provide novel hair care compositions having improved style and hold benefits.
It is another object of the present invention to provide novel hair care compositions having improved conditioning benefits.
These and other objects will become readily apparent from the detailed description which follows.